1. Field of the Invention
The present invention relates to method and apparatus for measuring aldehydes and, more particularly, to the improvement of an aldehyde capturing mechanism and an aldehyde measuring mechanism.
2. Description of the Prior Art
Environmental disruption due to the increase in the aldehyde concentration and environmental disruption in rivers and lakes due to the aldehydes contained in factory wastes have recently become a social problem, and a great importance has been made on the analysis of the aldehydes in the automobile exhaust gas, factory wastes, etc.
In conventional methods adopted so as to measure aldehydes in a gas, aldehydes are monitored by an infrared spectrometer connected to a gas cell, or the aldehydes are measured by colorimetry by bubbling an aldehyde-containing gas to dissolve the aldehydes in the gas into water.
However, in the method of monitoring aldehyde by an infrared spectrometer connected to a gas cell, the infrared spectrometer has too low a sensitivity for the continuous monitoring of the gaseous aldehydes having a low concentration such as a of the order of ppb and requires a complicated operation.
The method of measuring the aldehydes by capturing them in an aqueous solution by bubbling has a problem in the responsiveness to a change in the aldehyde concentration in a gaseous sample, and it is difficult to change various capturing conditions, so that this method also has difficulty in the continuous monitoring of the aldehydes in a gas.
On the other hand, for measurement of liquid aldehydes, colorimetry was conventionally used, but in order to improve the sensitivity, the chemiluminescence quantitative analysis of formaldehde has recently been applied. For example, a chemiluminescence analysis using oxalic ester TCPO (bis (2,4,6-trichlorophenyl) oxalate) after converting formaldehyde into a fluorescent derivative by using Fluoral-P(4-amino-3-penten-2-one) has been developed.
A conventional chemiluminescence quantitative analysis, however, cannot be said to produce a sufficient sensitivity, and is also disadvantageous in that the measuring operation is so complicated that the responsiveness becomes too much deteriorated for the continuous monitoring of the solvent which has captured the aldehydes in a gas or factory wastes.
Thus, a measuring method which provides a higher sensitivity with a simple operation has been demanded.